Process of making storage-battery electrodes.



H. C. HUBBELL.

PROCESS 0F MAKING STORAGE BATTERY BLEoTEoDEs.

APPLICATION FILED JULY 17, 1911.

Patented Apr. 7, 1914.

`HARRY CR-OSS H'UBBELL, NEWARK, NEW JERSEY.

PROCESS OF MAKING STORAGE-BATTERY ELECTRODES.

Specification of Letters Patent.

Patented Apr. 7, 1914.

Application led July 17, 1911. Serial No. 638,941.

To all whom it may `concern Be it known that I, Hanny CRoss HUB- nnnn, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Processes of Making Storage-Battery Electrodes, of which the following is a specification.

My ing an improvedstorage battery electrode which is oxidized on charge and which has' advantages'hereinafter pointed out. Nickel is the metal which I prefer inthe active material for the. electrode, but I may substitute therefor cobalt or iron.

Referring now to the accompanying drawing, Figure 1 is a diagrammatic sectional view showing the plunger 6 which is utilized to coperate with the die 7 in forming briquets under heavy pressure, .the bri-.

quet material 8 being located in the hopper 9, said materialbeing the oxid of nickel hereinafter referred to; Fig. 2 is a similar View, showing the cylinder 10, the cover 11, the asbestos lining 12 and the inlet pipe 14 for the hydrogen or illuminating gas, thel briquet 13, and the heating iame 15, hereinafter referred to; Fig. 3 is a longitudinal Vsectionalview of an electrode hereinafter described, showing in assembly the tablets 16 (made as below-described after the briquets 13 shown in Fig. 2 are as below-described immersed in a dilute solution of sodium or potassium hydrate, then taken out andground into a fine powder land dried, and then briqueted into said tablets 16), theconducting strip 17 and the gauze envelop 18, hereinafter 'referred to; Fig. 4 is a perspective view, showing the pocket 19, the perforations 2O therein, and the silver oXid 21 rammed thereinto, hereinafter referred to in the paragraph hereof beginning The necessity and importance ofthe conducting strip, etc.; and Fig. 5 is a view similar to Fig. 3, showing one of the end electrodes and disclosing in assembly said tablets 16, said strip 17 and said gauze envelop 18, hereinafter referred to.

Similar reference characters refer to similar posts throughout the several vie-ws of the drawing. 4

Assuming that nickel is to be my active material I will describe' the preferred op-` eration of the process. `As declared in Fig. `1 I take an oxid of nickel 8 which is reduble by hydrogen, preferably black anhyinvention relates to a process of mak-4 p1 vasbestos 12 to prevent overheating the matetrede.

drous sesquioxid of nickel, and place the same in a hopper 9. This I form'into briquets 13 (see Fig. 3) under heavy pressure, utilizing 'fo-r purposes of illustration 'the plunger and die 7 shown in Fig. 1.,

which I then heat (and now see Fig. 2) in an atmosphere of hydrogen or ordinary illuminating gas transmitted through the pe 14 in an iron cylinder 10 (lined with rial where the heating iame 15 is applied to the cylinder) until the oxid is reduced to the metal, care being taken that the teinperature is not high enoughto fuse or'weld the material of the briquets. The top 11 of the cylinder is then opened preferably while still hot and the briquets immediately dumped into a dilute solution of sodium or potassium hydrate. In this way atmospheric oxidation of the finely divided nickel is prevented, which is important since/this would result in an electrolyticallyrinactive oxid. The material remains in the alkali so' lution for say half an hour whereupon the solution is drained off and the damp material is ground into a fine powder and thereafter dried. This powder I then again briquet into small tablets 16 (see Figs. 3 and 5) ready for use in the make-up of the elec- I find the material of these tablets exceedingly active and eilicient,but in order to hasten the complete oxidation throughout their mass, I prefer to mix with the material drate to amount to about ten per cent.

(10%) by weight of the whole mixture.

This addition increases the porosity of the tablet. 'The material so made whether with -or without the 'addition of the nickel hydrate takes up and parts with hydroxyl and in general oxidizes 'and reduces with surprising ease in an alkaline electrolyte.

I believe that the briquets as they come fro-m the retort are substantially finely divided nickel which ify in ftlie form of a loose powder would instantly oxidize in the air into an elect-olytically.inactive material,- but the fact that it is .in"the for'm'of briquets prevents this. 'Finally the alkaline solution into which the ieduc'ed material is dumped seems to effect. a change, vwhich givesl l the :material additional immunity against oxidation in4 the air, because the tablets formed as described fromthe ground and dried material that has been exposed' to `the air for twenty-four hours gives the,`

and becoming oxidized which the fine reduced material persists inv doing. Cobalt may be substituted for nickel in the above,- the 4process being substantially the same, except that itv is started with a hydrogen-reducible oxid of cobalt and the addition-material to facilitate oxidation through `the mass will be a cobalt-hydrate. similarly be substituted for the nickel, in which event I can use the resultingelectrode both as the oxygen Astoring element on charge andl as the reduced element on charge.

. lVhen used as the oxygen storing element I prefer tolmix with the iron material about ten per cent. (10%) of iron monoxid; and when used as the reduced element I prefer to mix with it ten per cent. (10%) of cadmium oxid.

The tablets 16 above spoken of, vI prefer to make about $6 square and from l.; to thick. I then take a conducting strip 17 (scc Fig. 3), preferably a'nickel-plated iron strip 11.x5{ for a small portable battery and assemble 18 of these tablets 16 flat against each side of the strip. The Whole is -then fitted into a containing'euvelop 18 of nickel-plated iron gauze (see said Ifig. This produces what I calla double plate or electrode'. The important fact here is the middle conducting strip which makes it unnecessary to mix conducting nickel or other filaments with the active material, thereby eliminating the expense andincreased bulk and trouble thereon. Further. the conduct-- `ing strip permits the tablet= to be made thicker than would votherwise be possible and yet obtain oxidation as Well as the re-. verse electrolytic action through the mass.

The necessity and importance of the conducting strip may be made plain froml the following experiment. I chemically formed silver oxid and rammedit down as shown at 21in Fig. 4 into a pocket 19 having sides of metal'with perforations 20. The plate so produced was about 6 long, 1 Wide and thick. /Vhen made into a primary battery in an alkaline solution with an amalgamated zinc, I obtained a discharge .of something like 8 ampere-hours. I then used the couple as a storage battery in the attempt to reform the silver oxid from the spongy silver, but Was unable to do so to any substantial depth,

the Whole interior of the plate remainingv uny 4 oxidized in spite of many hours of attempted electrolytic oxidation. It seems that the silver oxid, formed von the surface, (good con` ducting compared to other oxids as it is) Iron mayl Was of high enough resistance to practically cut off 'the interior mass of sponge silver, in spite of the fact that rthere is practically no metal so easily oxidized and reduced as silver in. an alkaline solution. I then took the same plate rand put a thin strip of metal, say

copper or nickel, down through the center of it with the Asponge silver on either side and upon subjecting it to electrolytic oxidation found that-it was practically easy tol oxidize the. sponge silver completely. In

short. the experiment shows that it was imdescribed. v

For the end electrodes (and now see Fig.` 5) I put thetablets 16 on only-one side -of the conducting strip 17, which then constitutes one side of the container, the other side being the nickel-plated gauze 18. In this case the electrode is' only of about one-half the thickness of the first described or double electrode. It will be understood that the end electrode 'is positioned, so that 'its'gauze orv perforated side 18 faces inwardly toward the adjacent electrode, Whereas its other side, consisting of thenOn-perforated conducting strip 1T, faces oppositely. Further it will be understood that the conducting strip in the end electrode has the same function already described of insuring thorough oxidation and reversely reduction of the active material.

The advantages of the new electrode in an alkaline storage battery' are :1. It has great capacity proportionate to its size, which is adapted to. be unusually compact. 2. It is cheap to manufacture since it may be used without conducting filaments. 3. It is easily formed 1 4. It has low internal resistance Vso and high current delivering .capacit-y. 5. It.

does not distort.

In stat-ing that the oxid material during the reducing operation is in briqueted formv this does not meanthat the material is necessarily in regular shaped bricks or tablets, although this is preferable, but it does mean essentially thatthe material is aggldmerated into masses as distinguished'from being reduced in tine or powder form.l

The final briqueting of the material may consist` of packing it directly into thelpocket of the containing. envelop and this equivalent is intended to be covered by this briqueting step in the claims.

Some of the equivalents for the purpose of this invention of nickel oxid and the other materials specifically named herein have already been pointed out, and suoli expressions as nickel oxid, etc., in the claims are intended to include these and all other equivalents Within the spirit of the inven-N tion.

What I claim is:

1. The process of making an active mate rial for a storage battery electrode which comprises briqueting a nickel oxid, reducing it in said briquets by heat in a reducing atmosphere, submerging the hot reduced material in an alkali solution, grinding the damp material, drying it and rebriqueting.

2. rlChe process of making an active material for a storage battery electrode which comprises briqueting a nickel oxid. reducing it in said briquets by heat in a reducing atmosphere, subinerging the'hot reduced material in an alkali solution, and mixing and rebriqueting this material With a nickel hy drate or its equivalent.

3..The processor' making an active mateposure to the air treating the reduced material with an alkali solution.

5. The process of making an active material for' a storage battery electrode which comprises briqueting a nickel oxid, reducing it in said briquets by heat in a reducing atmosphere, and then without substantial exposure to the air treating the reduced material with an alkali solution and briqueting the resulting material.

6. The process of making an active material for a'storagc battery electrode which comprises briqueting a nickel oxid, reducing it in`said briquets by heat in a reducing atmosphere, andthen without substantial ex` posure to the airtreating the reduced material with an alkali solution, mixing with nickel hydrate and briqueting the resulting material.

7. The process of making an active material for a storage battery electrode which comprises briqueting a nickel oxid, reducing 1t in said briquets by heat in a reducing atmosphere, and then without substantial eX- posure to the air treating the reduced mate-" rial With an alkali solution, and mixing the resulting material With a proportion otl a metallic hydrate to facilitate' thorough oxi- .lation of the mass in forming the electrode wherein-the material is used 8. The process of making an active material for a storage battery electrode Whf'h comprises briqueting and then reducing a nickel oXid and then Without substantial exposure to J[he air treating the reduced material With an alkali solution.

9. The process of making an active material for a storage battery electrode which comprises briqueting and then reducing a nickel oxid and then Without substantial exposure to the air treating the reduced 1nate rial with a non-oxidizing liquid.

10. The process of making an active material for a storage battery electrode which comprises briqueting and then reducing a nickel oxid and then Wit-hout substantial exposure to the air treating the reduced mate! rial with a non-oxidizing liquid, and briqueting the resulting material.

11. The process of making an active inaterial for a storage battery electrode Which comprises briqueting and then-reducing a nickel oxid and then Without substantial exposure to the air treating the reduced material with a non-oxidizing liquid, draining off said solution, grinding the damp material, drying and briqueting it.

12.' The process of making an active materia'l for a storage battery electrode which comprises briqueting vand then reducing a nickel oxid by heat in a reducing atmosphere, the heat being moderated so as not to melt or usethe reduced material particles, and then without substantial exposure to the air treatingthereduced material with an alkali solution.

13. The process of making an active material fora storage battery electrodel which comprisesebriqueting the black sesquioxid of nickel, reducing it in said briquets by heat in a reducing atmosphere, submerging the hot reduced material in an alkali, solution, grindingthe damp material With a nickel hydrate, and rebriqueting.

14. The process of making an active 'maf teriall for a' storage battery electrode which comprises briqueting the black sesquioxid of nickel, reducing it in said briquets by heat in a reducing atmosphere, sbmerging the hot reduced 'material in an alkali solution, and mixing and rebriqueting this material With a nickel hydrate.

15. The process of making an active material for astorage battery electrode which comprises briqueting the black sesquioxid of nickel, reducing it in said briquets by heat in a reducing atmosphere, and then Without substantialv exposure to the air treating the reduced material with an alkali solution.

16. The process of making an active material for a storage battery electrode which comprises reducing the black sesquioxid of nickel in briquet form, and xrthen` without substantial exposure to the air" treating the reduced material with an alkali solution.

17. The process of making an active material for a storage battery electrode which comprises briqueting black anhydrous sesquioxid of nickel,l reducing it in said .bri-

quets by heat in a, reducing atmosphere, and

then Without substantial exposure to the air treating the reduced material with' an alkali solutio l 18. The process of making an'active .material for a storage battery electrode which comprises reducing the black anhydrous ses- `quioXid of nickel in briquet form, and then Without substantial exposure to the air covering the reduced material With a non-oxidizing liquid.

19. The process of making an active ma; terial fora storage battery electrode, which comprises reducing a nickel oxid in briquet form by heat in a reducing atmosphere at a temperature which does not substantially 2o melt or fuse the' particles, and then cooling the material out of contact with the air.

20. The process of making an active material for a storage battery electrode, which comprises reducing a nickel oxid in briquet 25 form by heat in areducing atmosphere at al temperature which does -not vsubstantially melt or fuse the particles, and then. cooling the material out of contact With .the air, and

regrinding and briqueting the material. 30

Gopes of this patent. may be obtained'lfor five cents each, by addressing the Commissioner of Patents,

Washingtoml). C. l 

